As entrepreneurs and creative workers, we should use our brains mainly for creative problem solving, and use simple rules for most other kinds of decisions. It keeps us happier.

I finally have an assistant, and he is awesome. I can tell him, "These are the cities and events on my global book tour, now go, and book me some good flights and hotels."

Obviously, this required that I first had to codify how I usually make decisions regarding my travels and accommodation. Economy class for short distances. Business class for the long hauls. Hotels near the venue exceptwhen the event is in a dull location. Direct flights preferred exceptwhen they cost over two times more. Only four-star hotels, and in the case of equal choices, pick the one with the highest rating.

Our brains use thousands of simple rules to navigate the complexity of the world. We cannot afford to deliberately think about everything we are confronted with. There is only so much time available in our lives and too many decisions to make. The rules we pick often have reasons attached at the time they are created. For example, I don't care about window seats versus aisle seats. What I want is a seat near the front of the plane so that I'm one of the first to get out and swiftly walk to immigration or the next flight.

But good reasons may evaporate over time while the rules get stuck in our behaviors, and then we're left with little more than a silly habit.

Hiring an assistant is a great thinking exercise. It forces you to explicitly evaluate your personal rules. You hold up a mirror and ask yourself, "Why am I always doing things like this?" Because you want to be sure the assistant does things for a good reason and not just because he's taking over your quirky habits. For example, I have a good reason for not wanting to set my alarm to go off at 3 a.m. in the night to catch a flight at 6 a.m. I travel so much that I prefer health and comfort over the cheapest flight tickets.

Once you've defined the rules and handed them over to your assistant, you can lean back, relax, and think about the most important things in your work-life that cannot be delegated. You can sit back and answer questions, such as:

What is needed to scale our small business?

Which people should I reach out to in order to grow my network?

What kind of company do I want to have five years from now?

You cannot properly handle such creative problem solving as long as the capacity of your brain is required to make decisions about visa application forms and frequent flyer programs.

It is for the same reasons that I define rules for the many requests that I receive every day. I cannot afford the time to consider whether to write an article for some blog or not, whether to do a free speech or not or whether to accept a dinner invitation or not. I need my brain to do creative problem solving and not worry about offending this person or disappointing that organization. This is why I have simple rules for blog articles, free speeches, dinner invites and much more.

My rules speed up my decision-making, and allow me to think about more important problems, and the thinking I do about interesting challenges is why people send me all those requests in the first place. They don't invite me to dinner to hear my thoughts about airline fares or dinner menus.

Granted, simple rules do not always lead to optimal decisions. Some itineraries could have been smarter if I had given it some thought. Some opportunities that I dismissed might have been great if I had really taken the time to look into them. But that's the point: If I spend time optimizing each decision, I won't have an interesting work-life left to make all those decisions about. It would make me quite unhappy.

And who likes having dinner with an unhappy person?

More from Entrepreneur

Kathleen, Founder and CEO of Grayce & Co, a media and marketing consultancy, can help you develop a brand strategy, build marketing campaigns and learn how to balance work and life.